This specification covers two-part, addition cured, high temperature resistant silicone sealing compounds. This product is used primarily for sealing aircraft firewall structures against passage of air and vapors. The cured compound shall remain an effective sealant at all temperatures between -65 and +400 degrees F (-654 to +204 degrees C) and shall be able to withstand a flash temperature of 2000 degrees F (1093 degrees C).